U.S. patent number 8,168,319 [Application Number 12/340,618] was granted by the patent office on 2012-05-01 for portable computer battery structures.
This patent grant is currently assigned to Apple Inc.. Invention is credited to Robert L. Coish, Michael D. Hillman, Chris Ligtenberg, Bradley L. Spare.
United States Patent |
8,168,319 |
Spare , et al. |
May 1, 2012 |
Portable computer battery structures
Abstract
Portable computer battery structures are provided. The portable
computer battery structures may include a battery with a metal
enclosure and a battery cable with a floating end. The battery may
have six cells. Three pairs of parallel-connected cells may be
connected together in series. The six cells may be substantially
planar in shape. The battery may have a connector with at least
five conductive pins and six recesses. The battery cable may have a
cable with at least five conductive pins that mate with the five
pins of the battery's connector and with six support pins that
slide into the six recesses of the battery's connector. The batter
connector may be formed on a printed circuit board substrate that
folds over on itself.
Inventors: |
Spare; Bradley L. (Oceanside,
CA), Hillman; Michael D. (Los Altos, CA), Coish; Robert
L. (Mountain View, CA), Ligtenberg; Chris (San Carlos,
CA) |
Assignee: |
Apple Inc. (Cupertino,
CA)
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Family
ID: |
42099140 |
Appl.
No.: |
12/340,618 |
Filed: |
December 19, 2008 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100092845 A1 |
Apr 15, 2010 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61105039 |
Oct 13, 2008 |
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Current U.S.
Class: |
429/159; 429/90;
429/99; 429/121; 49/7 |
Current CPC
Class: |
H01M
50/20 (20210101); H01M 50/543 (20210101); H01M
6/42 (20130101); H01M 50/209 (20210101) |
Current International
Class: |
H01M
2/10 (20060101); H01M 2/20 (20060101); H01M
2/02 (20060101); H01M 10/48 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Crepeau; Jonathan
Attorney, Agent or Firm: Treyz Law Group Kellogg; David C.
Treyz; G. Victor
Parent Case Text
This application claims the benefit of provisional patent
application No. 61/105,039, filed Oct. 13, 2008, which is hereby
incorporated by reference herein in its entirety.
Claims
What is claimed is:
1. A laptop computer battery comprising: a plurality of battery
cells; a battery connector; wires that connect the battery cells to
the battery connector; and a sheet of metal wrapped around the
plurality of battery cells and the wires to form a sleeve, wherein
the sheet of metal has a bent portion forming a hem along an edge
of the battery.
2. The laptop computer battery defined in claim 1 wherein the hem
includes adhesive.
3. The laptop computer battery defined in claim 1 further
comprising a conductive bus that electrically connects at least
some of the battery cells together and that is disposed along a
side of the battery cells, wherein the sleeve comprises portions
defining an opening through which the battery connector is
accessed.
4. A laptop computer battery comprising: a plurality of battery
cells; a battery connector; wires that connect the battery cells to
the battery connector; and a sheet of metal wrapped around the
plurality of battery cells and the wires to form a sleeve, wherein
the battery cells comprise: a first set of three planar battery
cells; and a second set of three planar battery cells, wherein the
battery cells in the first set are positioned adjacent to each
other along a horizontal direction, wherein the battery cells in
the second set are positioned adjacent to each other along the
horizontal direction, wherein each of the battery cells has a
substantially square surface, and wherein the surfaces of the
battery cells in the first set are aligned with the surfaces of the
battery cells in the second set.
5. The laptop computer battery defined in claim 4 further
comprising double sided tape between the first and second sets of
battery cells.
6. The laptop computer battery defined in claim 4 further
comprising a frame and an electrically insulating sheet, wherein
the battery cells are mounted within the frame, wherein the
electrically insulating sheet is wrapped around the frame and the
battery cells, and wherein the sleeve encloses the electrically
insulating sheet.
7. The laptop computer battery defined in claim 4 further
comprising a battery management unit.
8. The laptop computer battery defined in claim 7 wherein the
battery management unit comprises battery management circuitry on a
battery management substrate and wherein the battery management
substrate is folded back upon itself to form two substantially
parallel layers.
9. The laptop computer battery defined in claim 8 further
comprising a thermistor that is connected to the battery management
circuitry and that is thermally connected to at least one of the
battery cells, wherein the battery management circuitry is
configured to measure the resistance of the thermistor to determine
the temperature of the battery cell.
10. A battery comprising: a plurality of battery cells; a battery
enclosure that encloses the battery cells; a battery management
circuit substrate, wherein the battery management circuit substrate
is folded back upon itself to form two substantially parallel
substrate layers; and battery management circuitry on the two
substantially parallel substrate layers, wherein the battery
enclosure is formed from a layer of sheet metal that has a hem.
11. The battery defined in claim 10 wherein the battery management
circuit substrate comprises a rigid flex substrate that is folded
back upon itself to form the two substantially parallel substrate
layers.
12. The battery defined in claim 11 further comprising a ground
spring and a battery connector, wherein the ground spring is
mounted on a first one of the two substantially parallel substrate
layers of the rigid flex substrate and wherein the battery
connector is mounted on a second one of the two substantially
parallel substrate layers of the rigid flex substrate.
13. The battery defined in claim 10 further comprising an
insulating structure between the two substantially parallel
substrate layers.
14. The battery defined in claim 10 further comprising an
insulating sheet wrapped around the battery cells.
15. The battery defined in claim 10 further comprising a flame
resistant fiber sheet wrapped around the battery cells.
16. The battery defined in claim 10 wherein the layer of sheet
metal is folded back upon itself along a first edge and wherein the
hem is disposed along a second edge that is opposite the first
edge.
17. The battery defined in claim 10 wherein the layer of sheet
metal is folded back upon itself along a first edge, wherein the
hem is disposed along a second edge that is opposite the first
edge, and wherein the hem comprises a folded portion of the sheet
metal and an adhesive.
Description
BACKGROUND
This invention relates to electronic devices and, more
particularly, to battery structures for electronic devices such as
portable computers.
Designers of portable computers are faced with competing demands.
For example, it is generally desirable to reduce the weight and
size of a portable computer, so that a user is not burdened by an
overly heavy or overly large device. At the same time, performance
characteristics such as battery life should not suffer. Often, the
size of components such as a battery can be reduced, but only at
the expense of reducing battery capacity and therefore battery
life. For example, conventional batteries may include relatively
bulky battery management circuits and relatively bulking battery
enclosures or casings.
It would therefore be desirable to be able to provide improved
batteries, battery subsystems, and battery enclosures for
electronic devices such as portable computers.
SUMMARY
Portable computers with improved battery subsystems are provided. A
battery may include battery cells mounted within a battery
enclosure. The battery enclosure may be formed from metal. For
example, the battery enclosure may be formed from a layer of sheet
metal. A hem along one edge of the battery enclosure may be formed
using a folded portion of the sheet metal and an adhesive. A metal
end wall may be provided that occupies a small volume. A stacked
mounting structure may be used to house an integral battery
management unit. A window in the battery enclosure may be used to
allow battery contacts to mate with a floating battery cable in a
portable computer.
The battery may have six substantially planar cells that are
connected together through a combination of series and parallel
electrically connections. For example, three sets of cells may be
formed by connecting together two cells in parallel for each set.
The three sets of parallel-connected cells may then be connected in
a series combination. With this type of arrangement, the battery
may produce a ground voltage, a voltage equal to the voltage of a
single cell, a voltage equal to the voltage of two cells in series,
and a voltage equal to the voltage of three cells in series while
each of these voltages is provided by two parallel-connected
cells.
The battery may have a connector with at least five conductors. The
five conductors may carry the ground voltage and three voltages
created by the parallel-series connected battery cells as well as
data signals that convey information about the battery such as the
battery's charge state and temperature to an electronic device.
Further features of the invention, its nature and various
advantages will be more apparent from the accompanying drawings and
the following detailed description of the preferred
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an illustrative portable computer
in accordance with an embodiment of the present invention.
FIG. 2 is a perspective view of an illustrative battery showing an
interior battery assembly and a battery sleeve in accordance with
an embodiment of the present invention.
FIG. 3 is an exploded perspective view of an illustrative battery
enclosure showing interior shims and spacers that may be used and
showing how an end wall may be connected to one end of the
enclosure in accordance with an embodiment of the present
invention.
FIG. 4 is an exploded perspective view of an illustrative battery
without its sheet metal sleeve structure in accordance with an
embodiment of the present invention.
FIG. 5 is a perspective view of a portion of a battery sleeve hem
structure that may be used in a battery enclosure in accordance
with an embodiment of the present invention.
FIG. 6 is a perspective view of an illustrative battery connector
that may be used in a portable computer in accordance with an
embodiment of the present invention.
FIGS. 7 and 8 are perspective views of an illustrative battery
management unit and an illustrative battery connector that may be
used in a battery in accordance with an embodiment of the present
invention.
FIG. 9 is a schematic diagram of an illustrative battery that may
be used in a portable computer in accordance with an embodiment of
the present invention.
FIG. 10 is a perspective view of an illustrative battery management
unit and battery connector that may be formed from a folded rigid
flex substrate in accordance with an embodiment of the present
invention.
FIGS. 11A and 11B are cross-sectional side views of a rigid flex
circuit board structure of the type that may be folded over on
itself and may be used as a battery management unit printed circuit
board structure mounted within a battery in accordance with an
embodiment.
DETAILED DESCRIPTION
The present invention related to batteries and battery subsystems
for portable computer. The battery may include battery cells
mounted within a battery enclosure formed from metal. A stacked
mounting structure may be used to house an integral battery
management unit. The stacked mounting structure may be formed from
a rigid flex circuit board structure that is folded back upon
itself. A window in the battery enclosure may be used to allow
battery contacts to mate with a floating battery cable in the
portable computer.
An illustrative electronic device such as a portable computer in
which a battery may be used is shown in FIG. 1. Portable computer
10 may be a laptop computer, as an example. As shown in FIG. 1,
portable computer 10 may have a housing 12. Housing 12, which is
sometimes referred to as a case, may be formed from one or more
individual structures. For example, housing 12 may have a main
structural support member that is formed from a solid block of
machined aluminum or other suitable metal. One or more additional
structures may be connected to the housing 12. These structures may
include, for example, internal frame members, external coverings
such as sheets of metal, etc. Housing 12 and its associated
components may, in general, be formed from any suitable materials
such as such as plastic, ceramics, metal, glass, etc. An advantage
of forming housing 12 at least partly from metal is that metal is
durable and attractive in appearance. Metals such as aluminum may
be anodized to form an insulating oxide coating.
Case 12 may have an upper portion 26 and a lower portion 28. Lower
portion 28 may be referred to as the base or main unit of computer
10 and may contain components such as a hard disk drive, battery,
and main logic board. Upper portion 26, which is sometimes referred
to as a cover or lid, may rotate relative to lower portion 28 about
rotational axis 16. Portion 18 of computer 10 may contain a hinge
and associated clutch structures and is sometimes referred to as a
clutch barrel.
Lower housing portion 28 may have a slot such as slot 22 through
which optical disks may be loaded into an optical disk drive. Lower
housing portion may also have a touchpad such as touchpad 24 and
may have keys 20. If desired, additional components may be mounted
to upper and lower housing portions 26 and 28. For example, upper
and lower housing portions 26 and 28 may have ports to which cables
can be connected (e.g., universal serial bus ports, an Ethernet
port, a Firewire port, audio jacks, card slots, etc.). Buttons and
other controls may also be mounted to housing 12.
If desired, upper and lower housing portions 26 and 28 may have
transparent windows through which light may be emitted (e.g., from
light-emitting diodes). This type of arrangement may be used, for
example, to display status information to a user. Openings may also
be formed in the surface of upper and lower housing portions to
allow sound to pass through the walls of housing 12. For example,
openings may be formed for microphone and speaker ports. With one
illustrative arrangement, speaker openings such as speaker openings
30 may be formed in lower housing portion 28 by creating an array
of small openings (perforations) in the surface of housing 12.
A display such as display 14 may be mounted within upper housing
portion 26. Display 14 may be, for example, a liquid crystal
display (LCD), organic light emitting diode (OLED) display, or
plasma display (as examples). A glass panel may be mounted in front
of display 14. The glass panel may help add structural integrity to
computer 10. For example, the glass panel may make upper housing
portion 26 more rigid and may protect display 14 from damage due to
contact with keys or other structures.
Computer 10 may have input-output components such as touch pad 24.
Touch pad 24 may include a touch sensitive surface that allows a
user of computer 10 to control computer 10 using touch-based
commands (gestures). A portion of touchpad 24 may be depressed by
the user when the user desires to "click" on a displayed item on
screen 14.
A perspective exploded view of an illustrative battery that may be
used in computer 10 is shown in FIG. 2. As shown in FIG. 2, battery
102 may include interior portion 40 and sleeve 32. Interior portion
40 may include any suitable battery cells such as lithium-ion
cells. Portion 40 may be inserted into sleeve 32 by sliding portion
40 in direction 44. When inserted, plastic end cap 42 forms an end
of the battery enclosure for battery 102.
Battery sleeve 32 may be formed from a thin sheet of metal that has
been folded to form an enclosure. The edge of the metal sheet may
be sealed along hem 38 by folding the sheet back upon itself.
Adhesive may also be included within the gaps along hem 38 to
further seal the battery interior from its exterior. Planar shell
portion 34 may have an opening 36 through which battery contacts on
the lower portion of endcap 42 may be contacted. When inserted into
computer 10, these contacts may make contact with a mating male end
of a battery cable.
When battery 102 is inserted into computer 10, opening 36 may allow
a male connector to protrude into endcap 42 and mate with a
corresponding connector inside endcap 42. For example, a connector
such as connector 108 of FIG. 6 may pass through opening 36 in
sleeve 32 and couple to a connector such as connector 74 of FIG. 4.
If desired, connector 74 may be secured to sleeve 32 and opening 36
by screws 35. Screws 35 may pass through openings 37 in sleeve 32.
With one suitable arrangement, screws 35 may be longer than screws
39, which may be used to secure endcap 42 to sleeve 32, and screws
96 of FIG. 3, which may be used to secure end wall 94 to sleeve 32.
This type of arrangement may ensure that screws 35 are long enough
to secure connector 74 to sleeve 32.
FIG. 3 shows how end wall 94 may be screwed into sleeve 32 using
screws 96. Sleeve 32 may be formed from a metal such as aluminum.
End wall 94 may also be formed from metal. The use of metal for
enclosing battery 102 allows the structures of the battery
enclosure to be compact. End wall 94 may be attached to sleeve 32
at the end of sleeve 32 opposite to that at which end cap 42 is
connected.
Foam 92 may be mounted to the inside surface of end wall 94 to help
provide shock resistance for battery 102. Plastic tab 82 may be
connected to the outer surface of sleeve 32 to help a user remove
battery 102 from the interior of computer 10.
Cleats 84 may be attached to the exterior of sleeve 32 in regions
86 (e.g., using adhesive). In regions 86, the sheet metal of sleeve
32 protrudes slightly inwardly so that cleats 84 may lie flush with
the surrounding portions of sleeve 32. Smooth interior walls in
sleeve 32 may facilitate insertion of interior portion 40 of
battery 102 into sleeve 32. To help ensure that the interior of
sleeve 32 is smooth, even in the presence of inward protrusions
under regions 86, spacer structures such as spacer 90 and shims 88
may be mounted in the interior of sleeve 32 adjacent to protruding
portions 86.
An exploded view of battery 102 is shown in FIG. 4. As shown in
FIG. 4, battery 102 may have lithium ion cells 52 or other suitable
battery cells. Cells 52 may be held together in part by pads 62
(e.g., double-sided tape 62 may hold the upper set of battery cells
to the lower set of battery cells). Cells 52 may have tabs 104 that
can be spot welded to conductive portions of bus bar 56. Bus bar 56
may be formed from polyimide with embedded conductive structures
such as copper structures. Openings in the polyimide of bus bar 56
may be made to selectively expose the copper structures. Tabs 104
may be spot welded to the copper structures that are exposed in
this way. Wires 64 may be electrically connected to the copper
structures. The ends of wires 64 may be connected to circuitry in
end cap region 42.
End cap portion 42 may include end cap plastic structure 80 and
battery management unit printed circuit board 76. Battery
management circuitry (e.g., one or more battery management
integrated circuits) may be mounted on printed circuit board 76.
Printed circuit board 76 may be formed from a rigid flex substrate.
The substrate may be folded back upon itself as shown in FIG. 4 to
form a two-layer board. The battery management circuit may be
formed on the two layers of the battery management circuit
substrate (E.g., the rigid flex substrate).
Insulating structures may be provided in battery 102 to prevent
shorts. Insulating structures may include insulating patch 78,
insulating strip 54, insulating structure 70, and insulating sheet
46. Insulating sheet 46 may be wrapped around cells 52 to complete
the assembly of battery 102 and to enhance the structural integrity
of battery 102. Insulating structures may be formed from flame
resistant fiber sheets or other suitable materials.
Battery management unit holder 72 may be used to support the two
portions of printed circuit board 76. Battery connector 74 may be
mounted to the upper surface of printed circuit board 76. Battery
management unit wall structure 68 helps to complete the end cap
structure 42 by providing interior and lower walls. Foam 66 may
help provide shock resistance. A die cut insulation layer 58 may
protect tabs 104 and bus bar 56 after spot welding. Die cut plastic
insert 60 may help provide a smooth surface that allows interior
portion 40 of battery 102 to slide into shell 32 during
assembly.
Frame 48 may be formed from plastic. During assembly of battery
102, cells 52 may be mounted in frame 48. After assembly is
complete and an electrically insulating fabric sheet 46 has been
wrapped around frame 48 and cells 52, interior portion 40 may be
inserted into sleeve 32.
FIG. 5 shows how the hem 38 of sleeve 32 may be formed by folding
sheet metal 102 onto itself (i.e., onto edge 100) at bend 96.
Adhesive 99 may be inserted into gap 98 to help seal hem 38.
A computer power cable that may be connected to battery 102 when
battery 102 is inserted in computer 10 is shown in FIG. 6. As shown
in FIG. 6, cable 106 may have connectors at either end such as
connector 108 and connector 110. Connector 110 may be connected to
the main logic board in computer 10 or other suitable circuitry.
The flat middle portion of cable 106 may be enclosed in a cover and
may be placed along the interior surface of housing 12. Connector
108 may be a male battery connector in region 112 of cable 106 that
mates with connector 74 of FIG. 4.
Connector 108 may have conductive pins (contacts) 135 and pins 137
that mate with corresponding contacts in connector 74 of FIG. 4.
Connector 108 may have support pins 134 and pins 136 that mate with
corresponding recesses in connector 74 when the connectors are
coupled together. Pins 134 and 136 may help to hold connectors 74
and 108 in proper alignment when connectors 74 and 108 are coupled
together.
The position in which battery 102 is inserted into computer 10 may
vary between insertion events. To accommodate this natural
variation in the position of battery connector 74, at least a
portion of cable 106 may be floating (i.e., not rigidly attached to
housing 12). This allows the end of cable 106 and connector 108 to
move slightly as needed when battery 102 is connected to connector
108 by a user.
FIG. 7 shows an enlarged view of the printed circuit board 76 and
battery connector 74 shown in FIG. 4. Circuit board 76 may have
circuitry that controls the operation of battery 102. Circuit board
76 may be electrically coupled to cells 52. Circuit board 76 may
also be connected to circuitry in computer 10 through cable
106.
Printed circuit board 76 may include any suitable components. For
example, circuit board 76 may include voltage regulator circuitry,
battery monitoring circuitry that protects cells 52 during charging
and discharging operations, and other suitable components.
Contacts 116 and 118 may be connected to battery cells 52 using
wires 64.
Connector 74 may have connector pins 114A, 114B, 114C, 114D, and
114E that connect to corresponding conductive paths in cable 106
when connector 108 mates with connector 74 (e.g., when battery 102
is installed in computer 10). With one suitable arrangement, pin
114A may be a ground power pin and pin 114E may be a positive power
pin.
If desired, one or more pins such as pins 114B, 114C, 114D, and
114E may be carry data signals between connector 74 and computer
10. For example, pin 114B may connect to a data signal path in
cable 106 through a corresponding data signal portion of connector
108.
Pins such as pins 114B, 114C, 114D, and 114E may also be redundant
power signal lines or data signal lines. As an example, pin 114C
may be a redundant ground power pin and pin 114D may be a redundant
positive power pin. If desired, one or more of pins 114A-E may be
used to convey thermistor signals, clock signals, data signals,
switching signals, intermediate voltage signals, and other suitable
signals.
One or more of the pins 114A-E may also be used to convey
intermediate power supply signals between computer 10 and battery
102. For example, pin 114A may be a ground power pin, pin 114C may
be a first intermediate voltage pin, pin 114D may be a second
intermediate voltage pin, and pin 114E may be a positive voltage
pin. With one suitable arrangement, the first intermediate voltage
corresponds to the voltage of a single cell 52, the second
intermediate voltage corresponds to the voltage of two cells 52,
and the positive voltage corresponds to the voltages of three cells
52. Each of these voltages may be regulated by circuit board 76 and
may be provided by multiple cells connected together in series and
in parallel through circuit board 76, as an example.
Ground springs 120 and 122 may electrically connect circuit board
76 to conductive sleeve 32. Springs 120 and 122 may be metal spring
contacts that engage with a conductive surface of sleeve 32. With
this type of arrangement, circuit board 76 may be grounded to
sleeve 32 by springs 120 and 122.
Pins 124A-E may convey power and data signals between connector 74
and circuit board 76. With one suitable arrangement, battery
contacts 124A-E are connected to electrical traces on circuit board
76.
Pads 128A and 128B may be intermediate voltage pads that are
connected to wires 62. Pads 128A and 128B may also be connected to
pins 114C and 114D, respectively. Circuit board 76 may receive
intermediate voltages through pads 128A and 128B and may convey
these voltages to computer 10 through connectors 74, 108 and 110
and cable 106.
Holes 130 in connector 74 may receive screws 35 (shown in FIG. 2).
Screws 35 may hold connector 74 firmly against opening 36 of sleeve
32 so that cable connector 108 can be connected to connector 74
without putting pressure on or warping circuit board 76.
Battery 102 may include temperature sensors. As shown in FIG. 8,
circuit board 76 may include one or more pads such as pads 126A and
126B. Pads 126A and 126B may be connected through wires 64 to
temperature sensors that are distributed amongst cells 52 to
measure the temperature of cells 52. The temperature sensors may be
thermistors and pads 126A and 126B may be thermistor pads. Circuit
board 76 may be able to obtain the temperature of cells 52 by
measuring the resistance of the thermistors through pads 126A and
126B.
As shown in FIG. 8, connector 74 may include one or more side
conductive contacts such as contact 132. Contact 132 may be a
grounding contact that connects a ground trace in cable 106 to a
ground trace in circuit board 76. Contact 132 may be used to convey
any suitable signals such as a ground voltage, data signals, or a
power supply voltage between circuit board 76 and cable 106.
FIG. 8 shows how connector 74 may have two enlarged regions 140 at
each end of the connector and four enlarged regions 138 between
contacts 114A-E. The enlarged regions may be enlarged relative to
the portions of connector 74 corresponding to pins 114A-E. The
enlarged regions at each end of connector 74 may be somewhat larger
than the enlarged regions between the pins 114A-E. With one
suitable arrangement, connector 108 may have enlarged structures at
each end of the connector 108 that fit within the enlarged regions
at each end of connector 74 when the connectors 74 and 108 are
connected together. Connector 108 may also have somewhat smaller
enlarged structures that fit within the enlarged regions of
connector 74 between the pins 114A-E. The enlarged regions of
connector 74 between pins 114A-E may also be referred to as
connector receptacles. Conductive portions of connector 108 between
all of the enlarged regions of connector 108 may couple with pins
114A-E. As an example, pins 114A-E may be receptacles that receive
the conductive portions of connector 108 and that bear against the
conductive portions of connector 108 when the connectors 74 and 108
are coupled together.
As shown in FIG. 8, Connector 74 may have four recesses 138 between
conductive pins 114A-E as well as two recesses 140 that are
relatively larger than the recesses 138 and that are located on
either side of connector 74 (e.g., adjacent to pins 114A and 114E).
When connector 108 of FIG. 6 is coupled to connector 74, support
pins 134 and 136 of connector 108 may slide into recesses 138 and
140, respectively. Conductive pins 135 and 137 of connector 108 may
the electrically couple to contacts 114A-E and 132 of connector
74.
FIG. 9 shows a schematic diagram of battery 102. As shown in FIG.
9, cells 52 of battery 102 may form a pack 132. Cells 52 may be
connected together in any suitable configuration. For example,
cells 52 may be connected together through a combination of series
and parallel electrical connections.
As shown in FIG. 9, a first set of three cells 52 may be connected
together in series and a second set of three cells 52 may be
connected together in series. The first and second sets of cells 52
may be connected together in parallel. With this type of
arrangement, battery 102 may generate multiple different voltages
that can be conveyed to computer 10 through circuit board 76. Each
cell 52 may generate a particular voltage across its terminals 104
(e.g., each cell 52 may generate a voltage such as 1.5 volts, 3.7
volts, or any other suitable voltage). If desired, terminal 116 may
be at a zero voltage or ground potential, terminal 128B may be a
single cell voltage above ground (e.g., 3.7 volts), terminal 128A
may be at the voltage of two cells connected in series (e.g., 7.4
volts), and terminal 118 may be at the voltage of three cells
connected in series (e.g., 11.1 volts). Terminal 116 may be
connected to contact 114A and terminal 118 may be connected to
contact 114E (as an example).
As shown in FIGS. 4, 7, and 10, printed circuit board 76 may be
formed from a rigid flex substrate that is folded back upon itself
to form a two-layer board. For example, as shown in FIG. 10,
circuit board 76 is folded back upon itself to form a two-layer
board having a first layer 77A and a second layer 77B. Circuit
board 76 may be folded back upon itself along folds 150 (e.g., a
curved portion of the rigid flex substrate of board 76). If
desired, insulating structures such as patch 78 and structure 70 of
FIG. 4 may be located between layers 77A and 77B (e.g., to prevent
shorts between the two layers of circuit board 76).
Battery management unit printed circuit board 76 may be formed from
a rigid flex structure that is folded back upon itself to form a
two-layer board. An arrangement of this type is shown in FIGS. 11A
and 11B. As shown in the cross-sectional views of FIGS. 11A and
11B, circuit board 76 may include rigid flex structures such as
rigid printed circuit board layers 152. Rigid printed circuit board
layers 152 may be formed, for example, from fiberglass-filled epoxy
or other suitable rigid dielectrics. Rigid flex circuit board 76
also contains flex circuit layers such as flex circuit layers 154.
Flex circuit materials that may be used for flex circuit portion
154 include polyimide and other flexible dielectrics. Conductive
traces (e.g., of copper, gold, or other suitable conductors) may be
patterned within layers 152 and 154 to form desired interconnection
patterns, electrical buses, etc.
As shown in FIG. 11A, at least some flex circuit portions in rigid
flex circuit board 76 extend between the two rigid circuit board
portions (e.g., layers 77A and 77B of circuit board 76), so that
some of rigid flex circuit board 76 is rigid (e.g., portions 156)
and some of rigid flex circuit board 76 is flexible (e.g., portion
158). As shown in FIG. 11B, rigid flex circuit board 76 may be
folded back upon itself to form a two-layer circuit board.
The use of battery management unit circuit board arrangements such
as the rigid flex arrangement of FIGS. 11A and 11B for battery
management components in battery 102 may help to reduce the volume
that the battery management components occupy which allows a
smaller endcap 42 to be used and increased the volume of battery
102 that can be devoted to cells 52 (e.g., which can improve the
energy density of battery 102 relative to conventional
batteries).
In addition, the rigid flex arrangement may allow connector 74 to
move slightly within battery 102. This may help to accommodate
natural variation in the position of battery connector 74 when
battery 102 is inserted into computer 10. For example, the rigid
flex arrangement of FIGS. 11A and 11B can allow connector 74 to
move slightly as needed when connector 74 is connected to connector
108 by a user.
The foregoing is merely illustrative of the principles of this
invention and various modifications can be made by those skilled in
the art without departing from the scope and spirit of the
invention.
* * * * *